// color helpers, inspiration from the jquery color animation
// plugin by John Resig
function Color (r, g, b, a) {
  var x = Color.rgba.length;
   
  while (-1<--x) {
    this[Color.rgba[x]] = arguments[x] || ((x==3) ? 1.0 : 0);
  }
   
  this.toString = function () {
    if (this.a >= 1.0) {
      return "rgb("+[this.r,this.g,this.b].join(",")+")";
    } else {
      return "rgba("+[this.r,this.g,this.b,this.a].join(",")+")";
    }
  };

  this.scale = function (rf, gf, bf, af) {
    x = Color.rgba.length;
    while (-1<--x) {
      if (arguments[x] != null)
        this[Color.rgba[x]] *= arguments[x];
    }
    return this.normalize();
  };

  this.adjust = function (rd, gd, bd, ad) {
    x = Color.rgba.length;
    while (-1<--x) {
      if (arguments[x] != null)
        this[Color.rgba[x]] += arguments[x];
    }
    return this.normalize();
  };

  this.clone = function () {
    return new Color(this.r, this.b, this.g, this.a);
  };

  var limit = function (val,minVal,maxVal) {
    return Math.max(Math.min(val, maxVal), minVal);
  };

  this.normalize = function () {
    this.r = limit(parseInt(this.r), 0, 255);
    this.g = limit(parseInt(this.g), 0, 255);
    this.b = limit(parseInt(this.b), 0, 255);
    this.a = limit(this.a, 0, 1);
    return this;
  };

  this.normalize();
}
Color.rgba = ['r','g','b','a'];
Color.base = ["#edc240", "#afd8f8", "#cb4b4b", "#4da74d", "#9440ed"];
Color.list = [];
Color.newById = function (i)
{
  var variation = 0;
  j = 0;
  while (Color.list.length <= i) {
    var c;
    if (Color.base.length == j) // check degenerate case
      c = new Color(100, 100, 100);
    else
      c = Color.parse(Color.base[j]);
    
    // vary color if needed
    var sign   = variation % 2 == 1 ? -1 : 1;
    var factor = 1 + sign * Math.ceil(variation / 2) * 0.2;
    c.scale(factor, factor, factor);
    
    Color.list.push(c);
    
    ++j;
    if (j >= Color.base.length) {
      j = 0;
      ++variation;
    }
  }
  
  return Color.list[i];
}

Color.htmlColors = {
  aqua:[0,255,255],
  azure:[240,255,255],
  beige:[245,245,220],
  black:[0,0,0],
  blue:[0,0,255],
  brown:[165,42,42],
  cyan:[0,255,255],
  darkblue:[0,0,139],
  darkcyan:[0,139,139],
  darkgrey:[169,169,169],
  darkgreen:[0,100,0],
  darkkhaki:[189,183,107],
  darkmagenta:[139,0,139],
  darkolivegreen:[85,107,47],
  darkorange:[255,140,0],
  darkorchid:[153,50,204],
  darkred:[139,0,0],
  darksalmon:[233,150,122],
  darkviolet:[148,0,211],
  fuchsia:[255,0,255],
  gold:[255,215,0],
  green:[0,128,0],
  indigo:[75,0,130],
  khaki:[240,230,140],
  lightblue:[173,216,230],
  lightcyan:[224,255,255],
  lightgreen:[144,238,144],
  lightgrey:[211,211,211],
  lightpink:[255,182,193],
  lightyellow:[255,255,224],
  lime:[0,255,0],
  magenta:[255,0,255],
  maroon:[128,0,0],
  navy:[0,0,128],
  olive:[128,128,0],
  orange:[255,165,0],
  pink:[255,192,203],
  purple:[128,0,128],
  violet:[128,0,128],
  red:[255,0,0],
  silver:[192,192,192],
  white:[255,255,255],
  yellow:[255,255,0]
};

Color.extract = function (element)
{
  var color, elem = element;
  do {
    color = elem.css("background-color").toLowerCase();
    // keep going until we find an element that has color, or
    // we hit the body
    if (color != '' && color != 'transparent')
      break;
    elem = elem.parent();
  } while (!$.nodeName(elem.get(0), "body"));

  // catch Safari's way of signalling transparent
  if (color == "rgba(0, 0, 0, 0)") {
    return "transparent";
  }
  
  return color;
}

// parse string, returns Color
Color.parse = function (str)
{
  var result;

  // Look for rgb(num,num,num)
  if (result = /rgb\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*\)/.exec(str))
    return new Color(parseInt(result[1], 10), parseInt(result[2], 10), parseInt(result[3], 10));
  
  // Look for rgba(num,num,num,num)
  if (result = /rgba\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]+(?:\.[0-9]+)?)\s*\)/.exec(str))
    return new Color(parseInt(result[1], 10), parseInt(result[2], 10), parseInt(result[3], 10), parseFloat(result[4]));
    
  // Look for rgb(num%,num%,num%)
  if (result = /rgb\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*\)/.exec(str))
    return new Color(parseFloat(result[1])*2.55, parseFloat(result[2])*2.55, parseFloat(result[3])*2.55);

  // Look for rgba(num%,num%,num%,num)
  if (result = /rgba\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\s*\)/.exec(str))
    return new Color(parseFloat(result[1])*2.55, parseFloat(result[2])*2.55, parseFloat(result[3])*2.55, parseFloat(result[4]));
  
  // Look for #a0b1c2
  if (result = /#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})/.exec(str))
    return new Color(parseInt(result[1], 16), parseInt(result[2], 16), parseInt(result[3], 16));

  // Look for #fff
  if (result = /#([a-fA-F0-9])([a-fA-F0-9])([a-fA-F0-9])/.exec(str))
    return new Color(parseInt(result[1]+result[1], 16), parseInt(result[2]+result[2], 16), parseInt(result[3]+result[3], 16));

  // Otherwise, we're most likely dealing with a named color
  var name = $.trim(str).toLowerCase();
  if (name == "transparent")
    return new Color(255, 255, 255, 0);
  else {
    result = Color.htmlColors[name];
    return new Color(result[0], result[1], result[2]);
  }
}
